The Lippe Bad Lünen pool is expected to draw 250,000 visitors a year, making the facility a breakthrough project for public green building and saving about a dollar per visitor in energy costs. The bath house was three years in the making, but it’s not completely new — a decommissioned district heating plant built in the sixties was reclaimed to house one of the pools. The original building went through a deep energy retrofit to meet the stringent building standard. The finished bath house has three indoor pools of various sizes and one outdoor pool.